1. Technical Field
The present disclosure relates to a power conversion apparatus that converts direct current (DC) power into alternating current (AC) power.
2. Description of the Related Art
More and more companies and individuals are now selling power generated by distributed energy resources (for example, solar cells, fuel cells, and storage batteries) to power companies. Power can be sold through interconnection, in which the distributed energy resources and commercial power systems are connected to each other. In the interconnection, power conversion apparatuses called “power conditioners” are used for converting power generated by the distributed energy resources into power suitable for the commercial power systems.
If a distributed energy resource is a DC power supply, a power conversion apparatus that converts DC power into AC power is used in the interconnection. As this type of power conversion apparatus, for example, a grid-connected inverter apparatus has been proposed (for example, refer to Japanese Patent No. 4100125) that includes a high-frequency transformer, a first inverter that is arranged on a primary side of the high-frequency transformer and that converts DC power into high-frequency power, a current limiting reactor that is arranged on a secondary side of the high-frequency transformer and that converts the high-frequency power into commercial power, and a second inverter including a full bridge circuit in which a plurality of switching devices are bridged to one another. The switching devices of the second inverter are bidirectional switches that are turned on or off in accordance with the polarity of system voltage to convert the power of the high-frequency transformer into AC power.